Yes, biddies perambulating two abreast (4,2,4)

I believe the answer is:

side by side

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'abreast' is the definition.
(synonyms)

'yes biddies perambulating two' is the wordplay.
'yes biddies' can be anagrammed to 'SIDE BY SIDE'.
But, I'm not sure how this is indicated.

Can you help me to learn more?

(Other definitions for side by side that I've seen before include "Next to each other" , "As partners" , "Close together, abreast" , "Level" , "In tandem" .)

I've seen this clue in The Everyman puzzle in The Observer.

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